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

The annotations already declare readOnlyHint=true, so the description's main contribution is the 404 behavior: it specifies that a missing section or topic, or a topic owned by a different section, results in a 404. This goes beyond the annotation and helps the agent anticipate failure states. It does not describe the success response format, but given the read-only nature and no output schema, the 404 details are valuable and add transparency.

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 description is two short sentences, effectively front-loaded with the core action ('Retrieve a topic within a section') followed by the key error condition. There is no redundant wording or filler, and every sentence contributes useful information.

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 retrieval tool with two required parameters and readOnly annotation, the description covers the access scope and failure modes. However, it does not state what a successful call returns (e.g., the topic object), which is notable since there is no output schema. An agent might infer it returns the topic, but explicit mention of the success payload would make it more complete. The 404 details are helpful, but the absence of success-response description is a minor gap.

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 coverage is 100%, with both parameters having clear ID descriptions. The description adds the contextual relationship that the topic must belong to the given section, which is a semantic hint beyond the schema's simple ID labels. However, it does not elaborate on parameter formats, types, or constraints beyond what the schema states, so it only marginally supplements the 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?

The description states a specific verb ('Retrieve') and resource ('a topic within a section'), clearly distinguishing it from sibling tools like get_preference_section (retrieves a whole section) and list_preference_topics (lists topics). The phrase 'within a section' clarifies the hierarchical relationship, leaving no ambiguity about what the tool does.

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 gives clear context that the tool requires both a section and a topic, and implies it is used when you have both IDs. However, it does not explicitly name any alternative tool or state when not to use it. The 404 condition about a topic belonging to a different section adds usage nuance, but no direct comparison to siblings like get_preference_section or list_preference_topics. This is clear context without explicit exclusions.

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