AfterImage

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

With no annotations provided, the description carries full behavioral burden and does well: it discloses cache reuse, output fields (sha256 hash and fetched_at), the public-URL restriction, and the funded API key requirement. These are meaningful behavioral traits beyond a bare 'fetch page' statement.

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?

Three short sentences, each earning its place: what it returns, how caching works, and the key requirement. The most important information is front-loaded, with no filler.

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?

Despite no output schema, the description names the return contents (readable text, sha256 hash, fetched_at), covers both parameters through schema plus description, and gives the auth prerequisite. This is complete enough for an agent to select and invoke the tool correctly.

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 description coverage is 100%, so the schema already explains url and max_age_s. The description reinforces the caching semantics by saying 'Reuses a stored copy if it is newer than max_age_s,' but it does not add substantial new meaning beyond what the schema already provides.

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 states a specific verb and resource: 'Return readable text for a public http(s) URL.' It also clarifies caching behavior and output contents, which distinguishes it from the sibling search_pages by making clear this tool fetches a single URL rather than searching.

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 gives clear context for use: it applies to public http(s) URLs, can reuse cached snapshots based on max_age_s, and requires a funded API key. It does not explicitly mention when not to use it or compare it to search_pages, so it stops short of full alternative 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?

No annotations are present, so the description carries the full burden. It discloses two meaningful behaviors: no live-web access and the need for a funded API key. However, it omits other behavioral details like result ordering, pagination, or read-only implications. Adequate but not rich.

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?

Three short sentences with no filler. The most important scoping fact ('does not visit the live web') is front-loaded, and the API key requirement is included as a necessary caveat. Every sentence contributes.

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?

For a simple search tool with no output schema, it covers the essential context: the stored corpus, the live-web exclusion, the natural follow-up tool, and the authentication requirement. The only notable omission is the meaning of the limit parameter, though its default and bounds in the schema make it inferable.

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 describes q and max_age_s, but limit has no schema description. The tool description adds no parameter-specific information beyond what the schema provides, so it neither compensates for the missing limit description nor increases clarity. With 67% schema coverage, a baseline of 3 is appropriate.

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 states a specific action ('search') and a precise resource ('pages already stored in AfterImage'), and adds a distinguishing constraint: 'Does not visit the live web.' It also mentions the sibling get_page, making the tool's role clear.

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?

It explicitly clarifies this tool searches an offline corpus only, ruling out live-web queries, and provides a follow-up instruction: 'Then call get_page for the full text of a hit.' This is actionable, though it does not explicitly describe when get_page would be used alone or other alternative conditions.

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