discover_topics

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

Beyond the readOnlyHint annotation, the description adds rich behavioral detail: the exact JSON fields returned, newest-first ordering, snippet centering on body matches, default hiding of expired topics, the 'expired' marker when revealed, and reporting of truncation/hidden results. This fully discloses behavior without contradicting 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?

The description is front-loaded with the primary purpose and usage directive, followed by a compact list of return fields and behavioral notes. Every sentence contributes unique information; there is no padding or repetition of schema content.

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?

Given the tool's complexity (4 parameters, list return with fields, filtering, expiration handling), the description covers all essential aspects: what it returns, ordering, query behavior, expiry handling, and truncation reporting. With readOnlyHint annotation and output schema, nothing is left ambiguous.

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?

Input schema already covers all four parameters with descriptions (100% coverage), so baseline is 3. The description adds meaning beyond the schema, notably that query affects snippet centering and that include_expired reveals topics marked with 'expired': true. This enriches the agent's understanding of parameter effects.

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 'List available topics' — a specific verb and resource that distinguishes this discovery tool from siblings like read, write, and related. It also positions itself as the precursor to mutation operations, further clarifying its unique role.

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 instructs to 'Call this before read/write/edit/delete/append/rename/sweep', giving a clear when-to-use directive. It also explains optional query and include_expired behavior, which helps the agent decide when to pass those parameters.

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