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

Annotations already declare readOnlyHint=true, openWorldHint=false, and destructiveHint=false, so safety is covered. The description adds meaningful behavioral context beyond annotations: a per-element convolution method, natural-abundance basis, and validation against OpenMS.

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 a single front-loaded sentence with no filler, and the key resource is stated first. It is dense with parentheticals, which slightly reduces structural clarity, but every clause contributes relevant information.

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?

The tool has a full output schema and 100% schema description coverage, so return values and parameters are already covered. The description explains the output nature and computation method, but omits explicit guidance about record-based inputs and when to choose this over sibling tools.

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 baseline is 3. The description mentions peptide and elemental formula inputs with an example formula, but adds no meaning beyond what the schema already says about sequence, formula, charge, and maxIsotope.

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 states a specific resource and output: the relative heights and masses of M, M+1, M+2 peaks for a peptide or elemental formula. It distinguishes the result from fine-structure isotopic patterns, but does not explicitly name sibling tools such as isotopic_composition or peptide_mass to sharpen the distinction.

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 phrase 'as an instrument that does not resolve isotopic fine structure sees them' implies a usage context for low-resolution isotope patterns, and the formula/peptide inputs are named. However, it gives no explicit when-to-use conditions versus alternatives, so the guidance remains implicit.

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