indexnow-toolkit

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

With no annotations provided, the description carries the full burden and does well: it discloses that URLs are validated, that specific rules are enforced (same-host, 10000 limit, https/http consistency, fragment stripping, de-duplication), and that it returns reasons for dropped URLs. It does not explicitly mention error behavior for invalid keys, but 'validates' implies this, making the transparency strong.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is two sentences, each dense with distinct information: the first covers purpose and outputs, the second lists enforcement rules. There is no fluff or redundancy, and it is front-loaded with the tool's core function.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Given the tool has 5 parameters, no output schema, and moderate complexity, the description is quite complete: it explains what is returned (body, endpoint, curl, dropped URL reasons) and the validation rules applied. It could clarify what happens on invalid key or non-URL inputs, but overall it provides enough context for an agent to select and use the tool effectively.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

The schema already covers all parameters with descriptions (100% coverage), so baseline is 3. The description adds meaning by introducing constraints not present in the schema: the 10000-URL batch limit, https/http consistency, fragment stripping, and de-duplication, which notably apply to the urlList parameter. This enriches the agent's understanding of parameter validation expectations.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states the tool's purpose with a specific verb ('validates' and 'returns'), the resource (IndexNow POST body), and the concrete outputs (JSON body, endpoint, curl command, dropped URL reasons). It distinguishes itself from the sibling validate_indexnow_key tool by focusing on building a payload and validating both key and URL list, not just the key.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The usage is implied by the tool's name and description (build a payload, validate key/URLs), but there is no explicit mention of when to use this tool over validate_indexnow_key or diff_sitemaps. No alternatives are named or excluded, so the agent receives no direct comparative guidance.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

With no annotations, the description carries the transparency burden. It discloses accepted input formats, the diff logic (added, removed, lastmod-changed), the filtering to relevant URLs, and the optional key-driven POST body. This is sufficient for a read-only analysis tool.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is exactly two sentences, front-loaded with the main verb and object, and every clause adds value. No filler or repetition of schema details.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Given moderate complexity (6 params, no output schema), the description adequately covers inputs, processing, and output categories. It doesn't specify the exact return format, but the phrase 'reports added, removed and lastmod-changed URLs' gives enough guidance for an agent to interpret results.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is 100%, so baseline is 3. The description adds meaning beyond the schema by specifying the document formats for previous_sitemap/current_sitemap and explaining that the key can yield a 'finished, validated POST body.' This adds useful context to the parameters.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states the specific action: 'Parses two sitemap documents' and 'reports added, removed and lastmod-changed URLs.' It also names the output scope ('URLs worth submitting to IndexNow'), distinguishing this tool from siblings that build or validate messages.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description makes the primary use case explicit: diff two sitemaps to produce a submission list. It doesn't explicitly mention when to choose build_indexnow_payload or validate_indexnow_key, but the context implies the workflow, so there's no exclusion gap.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

With no annotations provided, the description carries the full burden. It discloses that the tool computes and returns the key file URL, contents, and curl command, implying it does not itself fetch the file. It also adds a useful diagnostic heuristic about 403 errors. However, it does not explicitly state whether the operation is read-only or if any external calls are made, leaving a small gap.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is two sentences with no fluff. The first sentence front-loads the primary purpose and outputs, while the second sentence adds a practical, non-essential troubleshooting tip. Every word earns its place; it is concise yet comprehensive.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Without an output schema, the description clearly explains the return values (exact URL, contents, curl command). It also gives a real-world context with the 403 error note. It could be slightly more explicit about edge cases (e.g., behavior when host is omitted) but is generally complete for this tool's simplicity.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

The schema descriptions are minimal ('The key to check', 'Optional host... to compute the key file URL'), but the main description adds meaning by explaining the relationship between host and the computed key file URL. This goes beyond the schema alone, making the parameter purposes clearer.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states the tool's function: 'Checks an IndexNow key against the protocol schema (length, character set)' and also describes the additional outputs (exact URL, contents, curl command). This specific verb+resource combination distinguishes it from sibling tools like build_indexnow_payload and diff_sitemaps.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description provides clear context on when the tool is relevant, especially the 403 rejection troubleshooting hint: 'Most 403 rejections are a key file that returns an HTML 404 page with a 200 status.' While it implies usage (validating keys and getting verification steps), it does not explicitly name alternatives or state when not to use it, so it falls slightly short of a 5.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.