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

Annotations already declare readOnly, idempotent, openWorld and non-destructive, so the safety profile is carried structurally. The description goes beyond that by disclosing the ranking mechanism (Arca index fused with PubMed Best Match) and the external enrichment sources (OpenAlex), which tells the agent why result order may differ from a plain PubMed query. What is missing is any note on latency, rate limits, or what happens when OpenAlex metadata is unavailable for a record.

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, front-loaded with the identifying verb phrase, and the second sentence is a compact enumeration of returned fields rather than prose padding. The result-field list is arguably redundant given the output schema exists, which is the only thing keeping it off a 5.

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 and annotations covering the safety profile, the description need not restate return shapes or side effects, and it correctly spends its words on ranking provenance instead. For an eight-parameter search tool with full schema coverage, that is close to sufficient. The remaining gap is routing guidance against search_medical, which no structured field supplies.

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 every one of the eight parameters is already documented in the input schema with bounds and defaults. The description only gestures at the filterable dimensions by naming citation count and open-access status among the returned fields, adding no format guidance, interaction effects, or semantics beyond the schema. Baseline 3 is the right landing point when the schema does all the parameter work.

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 and resource ("Ranked PubMed literature search") and explains what makes the result set distinctive: a fusion of Arca's paper index with PubMed Best Match, enriched with OpenAlex citation and open-access data. An agent knows exactly what corpus is being searched. It stops short of distinguishing itself from the sibling search_medical, which is the one ambiguity a reader would still have.

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?

There is no explicit when-to-use statement and no exclusion or alternative named, despite search_medical sitting right beside it as an obvious candidate for similar queries. The reader must infer from the name and the mention of PubMed that this is the biomedical-literature search path. No prerequisites or fallback guidance are given.

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