tcg_psa_pop_trend

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

Annotations already declare readOnlyHint, destructiveHint, and idempotentHint. The description adds critical behavioral context: the tool requires prior snapshot data and returns historical time series, which is beyond the annotations. No contradictions.

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?

Two sentences: first states the core action, second provides a usage example and a prerequisite. Front-loaded, no wasted words.

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 rich input schema, annotations, and output schema (present), the description covers the tool's purpose, use case, and dependency. It is sufficient for an agent to use correctly.

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?

The description does not mention any parameters (schema description coverage is 0%), but the input schema provides detailed descriptions for all four parameters (spec_id, cert_number, grade, days). Baseline 3 is appropriate as schema compensates.

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 tool returns a time series of pop snapshots for a card spec, uses a specific verb ('Return'), and distinguishes from siblings like tcg_psa_snapshot_pop by noting the prerequisite. The example 'Has PSA 10 pop for this card grown a lot?' adds clarity.

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 tells when to use ('for answering population growth questions') and when not to use ('only works for specs you've snapshotted via tcg_psa_snapshot_pop'), naming the prerequisite sibling tool. No alternative tools listed, but the condition is clear.

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