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

Annotations already declare readOnlyHint=true and openWorldHint=true, and the description adds value beyond them by disclosing the returned content (metadata and body paragraphs) and clarifying that only public articles are fetched. It does not mention rate limits or partial-content behavior, but given annotation coverage this is solid.

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, zero waste, and front-loaded with the core action before the routing guidance. 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?

An output schema exists, so return values need not be explained. The description states purpose, the required input, and how to obtain a URL via sibling tools, which is everything an agent needs to invoke it 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 description coverage is 100%, so the single 'url' parameter is already documented in the schema. The description only reinforces 'canonical' URL, adding no new format or syntax guidance, so the 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?

Specific verb ('Fetch') plus resource ('public Punch article metadata and body paragraphs') plus the required input ('canonical url'). It also names the sibling tools (punch_headlines, punch_news, punch_author) so an agent can distinguish it from the discovery tools without opening schemas.

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?

Explicitly routes the agent: use punch_headlines to find stories, punch_news for the general feed, punch_author for a byline profile. This states the alternatives and the conditions under which each is used, leaving little to inference.

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