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

Annotations already declare readOnly/idempotent/non-destructive/openWorld, so the safety profile is covered. The description adds genuine context beyond that: what each returned item carries (evidence type, level A-E, direction, significance, 1-5 star rating, disease, therapies, PubMed/ASCO source), which matters because there is no output schema. It doesn't mention pagination or result-count behavior.

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?

Three sentences, front-loaded with the core purpose, then the payload description, then the authoritative-vs-summary distinction and input options. Dense but every clause carries information; the payload enumeration is long but justified by the absence of an output schema.

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 no output schema, the description takes on the burden of describing returns and does so thoroughly (field list per evidence item), and it covers both input modes for a zero-required-parameter tool. An agent has enough to select and invoke 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 description coverage is 100%, so the schema already documents all six parameters including the limit range, filter semantics, and the molecular_profile vs variant_id alternative. The description's 'Pass a molecular profile name such as "BRAF V600E", or a numeric CIViC variant id' restates that without adding new syntax or constraint detail, so the baseline 3 applies.

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?

States a specific verb+resource: individual CIViC evidence items for a molecular profile, with the entity defined (graded, source-linked statements). It also draws the boundary against the sibling that summarizes rather than lists — 'AUTHORITATIVE for the clinical evidence behind a variant claim, rather than a summary of it' — which separates it from civic_assertions.

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?

It gives clear context for when to reach for this tool (authoritative source evidence behind a variant claim) and implies the contrast with a summary tool, plus it explains the two accepted inputs (molecular profile name or numeric variant id). It never names the alternative tool or states exclusions, so it falls short of a full 5.

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