flutter_docs

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

With no annotations, the description carries the full burden and does well: it discloses caching (the 'cached' field), truncation policy (cut at a line boundary with a trailing note, plus a 'truncation' field explaining what was cut and why), and the topic-filter fallback that returns full content plus a note listing available sections. It does not mention network, auth, or rate-limit behavior, which keeps it short of a 5.

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 core purpose is front-loaded in one sentence, followed by scannable indented blocks for identifier forms, args, and returns. Length is justified because the description is the only place the parameters and return contract are documented.

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?

Absent annotations and absent output schema, the description still supplies the full return shape (type, identifier, url, title, content, truncated, tokens, source_tokens, max_tokens, cached), the error shape with a 'suggestion', and the conditional fields. Nothing an agent needs to call or interpret this tool correctly 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 0%, so the description must compensate, and it does: identifier forms are spelled out with resolution order, topic is explained with its fallback semantics, and max_tokens is given units (1 token ≈ 4 chars) plus the truncation consequence. This is meaning well beyond the bare string/integer 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?

States a specific verb (Fetch), a precisely bounded resource (one Flutter / Dart SDK / pub.dev documentation page) and the output form (clean markdown). The word 'one' plus the three named source families make it distinguishable from the search-oriented siblings without opening any schema.

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?

It gives real invocation context by enumerating the identifier forms and the exact resolution order used to disambiguate them (pub:, dart:, library-qualified, bare name with index/fallback chain), which is the main usage decision for this tool. It stops short of explicitly routing between itself and overlapping siblings such as pub_package or flutter_search.

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