fetch_url

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

With no annotations provided, the description carries the burden of behavioral disclosure. It does mention caching locally, content type handling, and optional saving to docs/<slug>.md with YAML frontmatter. However, it omits details about side effects like overwriting files, the meaning of 'refresh' and 'no_anubis', and potential rate limits or errors.

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, front-loaded with the primary function, and every detail (content type handling, caching, saving) earns its place. It is efficient and well-structured without redundancy.

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 no annotations, no output schema, and low schema coverage, the description should provide more operational context. It explains the core workflow and optional save, but lacks details on refresh behavior, the no_anubis flag, file overwrite semantics, and return format nuances. It is sufficient for basic use but has notable gaps for a moderately complex tool.

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 only 17% (only 'url' has a description). The description partially compensates by mentioning the save feature (docs/<slug>.md) which relates to 'save', 'name', and 'subdir', but it does not explicitly explain these parameters or cover 'refresh' and 'no_anubis'. Thus, it adds some meaning but not enough to fully compensate for the undocumented 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 tool fetches a single URL and returns clean markdown, with specific handling for HTML, JSON, and plain text. It distinguishes from siblings like web_search by focusing on direct URL fetching 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 implies the tool is for fetching a specific URL when you have one, but it does not explicitly state when to use it over siblings or provide exclusion criteria. No alternatives are named, so usage guidance is only implied.

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