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

Annotations already declare readOnly, idempotent, non-destructive, closed-world behavior, so the safety profile is covered. The description adds genuine value by disclosing what each result contains: names, one-line summaries, FDA status, evidence level and page links. It does not mention result caps or pagination, which keeps it below a 5.

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, zero filler, and the matching scope is front-loaded before the return-value summary. Every clause carries information an agent can act on.

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 correctly compensates by enumerating returned fields, and it covers both parameters implicitly. The only gap is absence of any guidance on result volume or how to narrow a too-broad topic query, which matters for a search tool whose default lists everything.

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 both parameters are already fully documented in the schema, including the empty-string-lists-everything behavior. The description's topic examples (GLP-1, healing, weight loss, sleep) largely repeat the schema's own examples, adding little beyond it. Baseline 3 is appropriate.

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 and resource ('Lists the peptides TruePeptideSource covers') plus the matching dimension (name, alias, topic). It's clearly a discovery/search tool, but it never names how it differs from the closest sibling, peptide_lookup, leaving the search-vs-lookup boundary to inference.

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?

Usage is implied: agents can infer this is the entry point for discovering peptides by topic or name, while peptide_lookup would fetch a specific record. However, there is no explicit 'use this when...' statement and no mention of alternatives among the five siblings (compare, blend/reconstitution/supply calculators).

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