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

Annotations already declare readOnlyHint, idempotentHint and destructiveHint=false, so the safety baseline is covered. The description adds genuinely new context beyond the annotations: scoring happens in memory and text is never stored or logged, plus a note that include_raw produces larger output. That is useful privacy and cost context for a read-only tool.

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 that puts the deliverables first and the privacy/engine notes last. It is dense and long, but nearly every clause earns its place; only the API-equivalence clause is borderline filler.

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?

With an output schema present, the description need not spell out return values, yet it still summarizes them accurately (metrics, consensus grade, statistics, long sentences). Combined with the in-memory/no-logging note and API equivalence, an agent has everything needed to call it 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?

Schema coverage is 100%, so the baseline is 3, but the description adds downstream meaning the schema does not: it explains that long sentences above a threshold are surfaced, that raw results are unclipped, and that reading/speaking time and text statistics are included. This connects include_raw and long_sentence_words to observable output 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?

Names a specific verb (compute) and resource (readability scores for English text) and enumerates the exact metrics returned, so an agent knows precisely what this produces. It also identifies the underlying engine (PlainGrade JSON API POST /v1/score), which is useful disambiguation.

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 implies usage (score English text in memory) and notes the equivalence to the PlainGrade /v1/score endpoint, but gives no explicit when-to-use/when-not guidance and there are no siblings to differentiate against. Adequate but minimal.

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