Get HIG topic

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

With no annotations, the description carries the full disclosure burden and does deliver the output shape (Markdown plus canonical Apple URL) and the narrowing effect of section/platform. It says nothing about error behavior for an invalid slug, network/rate-limit characteristics, or how large an article may be, which are the gaps a caller would want.

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?

Three short sentences, front-loaded with the verb, resource, and return format, then the accepted input forms, then the two filters. No filler and nothing repeated from the schema verbatim.

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?

There is no output schema and no annotations, so the description must carry return semantics — it does (Markdown body plus canonical URL). Input flexibility and both optional filters are covered; only failure modes and remote-access constraints are absent, which is a minor gap for a read-only fetch 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 already 100%, so the baseline is 3. The description goes slightly beyond the schema by explaining the filter effect — 'section to keep one heading' and 'platform to drop other platforms' notes' — which clarifies that platform is a subtractive filter rather than just a target selector.

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 gives a specific verb and resource — 'Fetch one Human Interface Guidelines article as Markdown, with the canonical Apple URL' — and the word 'one' plus the output format distinguish it from list_topics and search_hig. It never names those siblings explicitly, so an agent must infer the routing rather than being told.

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?

'Accepts a slug, path, or developer.apple.com URL' and the note about section/platform tell the agent how to call it, but not when to choose it over search_hig (to discover a topic) or get_design_reference. Usage is implied by the input flexibility rather than stated with conditions or exclusions.

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