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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false, so the safety profile is established. The description adds useful behavioral context beyond that: the topic is 'public' (implying no special access), the ID is 'stable' (reinforcing deterministic retrieval), and the result includes references, related topics, and limitations. There is no contradiction with the annotations.

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?

A single, front-loaded sentence delivers the key action ('Read a public optical topic'), the lookup key ('by stable ID'), and the output highlights ('with references, related topics and limitations'). There is no filler, repetition, or unnecessary detail.

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 simple read-only tool with strong annotations and a closed enum for the ID, the description covers the core purpose and even hints at the return contents. The main gap is the undocumented 'language' parameter and the absence of any output shape details, though there is no output schema for the agent to fall back on.

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 for the two parameters, but it does not. It characterizes 'id' only as a 'stable ID' and never mentions the 'language' parameter, its allowed values, or its default of 'pt'. The enum values themselves are self-explanatory, but the language semantics are entirely undocumented in both the schema and the description.

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 verb ('Read'), the resource ('public optical topic'), and the lookup mechanism ('by stable ID'), and it even previews the return contents ('references, related topics and limitations'). It does not explicitly contrast itself with siblings like search_optical_knowledge or the calculators, so it misses the full 5 for sibling differentiation, but the intent is unmistakable.

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 phrase 'by stable ID' implies this is the right tool when the caller already has a known topic ID, rather than for free-text search or calculations. However, the description does not explicitly state when to prefer this tool over search_optical_knowledge or when a calculator would be more appropriate, leaving the routing largely to inference.

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