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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint, so the safety profile is covered. The description adds valuable behavioral nuance beyond annotations: default editorial/lexical assignments, the function of includeSemantic, the firstYears author constraint, and the crucial denominator detail that 'percentages use evaluable works, not semantic top-k results.'

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 four sentences with no filler. The core purpose is front-loaded, and each subsequent sentence adds a distinct piece of useful behavior. It is dense but not bloated.

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?

This tool has a complex nested filters schema, seven top-level parameters, zero schema descriptions, and no output schema. The description covers only a few operational specifics (includeSemantic, firstYears, percentage denominator) and omits key context about period definitions, interval semantics, filter behavior, and response structure, making it inadequate for fully correct invocation.

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?

With 0% schema description coverage, the description must compensate. It clarifies two important parameters: includeSemantic ('explicitly includes embedding associations') and firstYears ('requires exactly one author and starts at their earliest catalogued work'). However, it leaves periods, interval, pagination, and the interaction between periods and interval undocumented, so gaps remain.

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 opens with a specific verb-resource pairing: 'Compare precomputed thematic indicators by period.' This clearly identifies the tool's function and distinguishes it from siblings like get_topic_evidence, which focuses on evidence rather than period-based comparison of thematic indicators.

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 no guidance on when to choose this tool over alternatives such as get_topic_evidence or search_works. It provides operational constraints (e.g., 'firstYears requires exactly one author') but does not explain the scenarios that should route an agent to this tool versus its siblings.

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