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

With no annotations provided, the description must carry the full behavioral burden. It discloses the fallback to Common Crawl but omits critical behaviors such as error handling, handling of non-HTML content, rate limits, or whether the page text is truncated. The phrase 'extract readable page text' implies some processing but does not specify limitations.

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 a single sentence, which is concise and front-loaded with the primary action. However, it is under-specified given the three parameters and lack of annotations. The structure is acceptable, but the brevity leaves out important context, so it does not fully earn its place.

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?

The tool has no output schema and no annotations, so the description should cover return format, error conditions, and parameter effects. It only hints at the fallback behavior and says it extracts text. An agent cannot infer what happens if the URL is invalid, what max_chars does, or what the output looks like. The description is incomplete for reliable invocation.

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 0%, so the description must explain parameter meanings. It only obliquely references the archive_fallback parameter via 'optionally fall back to Common Crawl', but does not explicitly describe url or max_chars. The names are self-explanatory to some degree, but the description adds minimal value beyond the schema.

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 verb 'fetch' and the resource 'readable page text', which is specific and distinct from the sibling search tools. It also mentions the optional Common Crawl fallback, but that's behavioral rather than purpose. The purpose is unambiguous and immediately understandable.

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 no guidance on when to use this tool versus the search siblings. It does not state that this is for known URLs while search tools are for discovery. The only hint is the tool name itself, but that is not sufficient. No exclusions or alternatives are mentioned.

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