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

Annotations already declare readOnlyHint=true, so the safety profile is covered. The description adds value beyond that by disclosing the return shape (key, homepage, type, sector) and the alphabetical ordering, which is important for pagination behavior. No output schema exists, so this disclosure is genuinely useful.

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 compact sentences with zero padding; the core purpose is stated first, then the practical detail about the key field. Every clause earns 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?

For a read-only listing tool with no output schema, the description covers purpose, filtering, ordering, and the fields returned, which is everything an agent needs to call it and interpret the result. Nothing material is missing.

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 pagination and country parameters are documented in the schema and the baseline is 3. The description adds one thing the schema does not: results are sorted alphabetically, which matters for reasoning about paging, and it restates the country filter as an optional scope.

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 ('List the news publishers World Feed Monitor reads') plus ordering and an optional filter. It is clearly a directory/lookup tool, distinguishable from siblings like search_news and get_latest_news, which it explicitly references.

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 explains the downstream workflow: each entry has a key to pass as `source` to search_news or get_latest_news, which tells the agent exactly why and when to call this tool. It lacks an explicit exclusion statement (e.g., 'do not use this to fetch articles'), keeping it at 4.

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