fetch

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

The annotations already declare readOnlyHint=true and idempotentHint=true, indicating safe, idempotent behavior. The description adds that the tool returns reader-mode Markdown of the main content, which provides some behavioral context (e.g., extracting readable article content). However, it does not disclose additional traits like rate limits or response size beyond what annotations imply.

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 brief and front-loaded, with the main action stated first, followed by a compact parameter list. Every sentence and line is necessary; no extraneous information.

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 the complexity (4 parameters, annotations, and an output schema), the description is largely complete. It explains the core functionality and all parameters. However, it does not clarify differences between 'markdown' and 'json' output formats, which could be inferred from the output schema but is not explicitly stated. Overall, it meets the requirements without major gaps.

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 input schema has 4 parameters with 0% description coverage, so the description compensates by explaining each parameter: url (absolute http(s) URL), extract_code (extract code blocks, default false), extract_tables (extract table data, default false), and format (markdown or json). This adds meaning beyond the schema's type and defaults.

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 one URL and returns reader-mode Markdown of the main content. The verb 'fetch', resource 'URL', and output 'reader-mode Markdown' are precise. The tool name and description differentiate it from siblings like 'fetch_batch' (multiple URLs) and 'extract_structured' (structured extraction).

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 through the name and parameter details, but does not explicitly state when to use this tool over alternatives such as 'fetch_batch' or 'extract_structured'. No guidance on context or exclusions is provided.

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