fetch_page

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

With no annotations, the description carries the full burden and does so well: it discloses the extraction method, the markdown return format, the character ceiling, explicit failure modes (403, 429, empty result) with instructions not to guess, and a prompt-injection warning to treat fetched content as data. This is unusually rich behavioral context for a read 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?

Front-loaded with the triggering condition and input source, then layers output, limits, failure handling, and the security caveat in compact sentences. Every sentence earns its place 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 lacking annotations and an output schema, the description covers what is fetched, how it is transformed, the size bound, and what to do on failure, which is everything an agent needs to invoke and interpret results 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 coverage is 100%, so both url and max_chars are already fully documented in the schema. The description's mention of 'Returns up to 15000 characters' merely echoes the schema default rather than adding format or syntax detail. Baseline 3 applies.

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?

States a specific verb and resource ('read the full content of a page') and names the sibling it follows (web_search), plus the extraction mechanism (Readability) and output format (markdown). An agent can tell it apart from web_search and fetch_llms_txt without opening any schema.

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?

Explicit sequencing guidance ('Use this AFTER web_search', 'Give it a URL from the search results') tells the agent exactly when to reach for it and what input to supply. It stops short of stating when NOT to use it versus the fetch_llms_txt sibling, so it is strong but not fully exclusionary.

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