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

Annotations already establish readOnly/openWorld/idempotent/non-destructive, so the safety profile is covered; the description adds genuinely new behavioral context by disclosing the credit cost model, including the surcharge for summaries/questions and further surcharges for very long answers. It still does not cover latency or failure behavior for unreachable pages.

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?

Two sentences, front-loaded with the core action and output format, followed by the optional capabilities and the cost model. The cost sentence is dense but every clause carries operative information; nothing here is 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?

With rich annotations, a full output schema, and 100% parameter coverage, the description only needs to supply the additional context the structured data cannot carry, and it does so via the credit-cost disclosure. Pagination mechanics (offset/max_chars) are left entirely to the schema, which is acceptable but slightly reduces completeness for a 9-parameter 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 100%, so every parameter (fresh, format, mobile, offset, question, max_chars, wait_for_ms, only_main_content) is already documented in the schema. The description's mention of question/summary adds only a light reinforcement of what the schema already states, so the baseline of 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?

The description names a specific verb and resource ('Fetch one web page or document and return its main content as compact markdown') and scopes it to a single page, which distinguishes it from multi-page siblings like ragfeed_crawl and from ragfeed_extract/ragfeed_map. The parenthetical about boilerplate removal further pins down what 'content' means.

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 usage via 'Optionally answer a question about the page or summarize it', which maps to the question/format=summary options, but it never says when to prefer this over ragfeed_crawl, ragfeed_extract, or ragfeed_map. No explicit when-not or alternative-routing guidance is given.

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