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

Annotations already establish that this is a safe read-only, closed-world operation, so the description only needs to add beyond that. It does contribute one useful behavioral fact: results come from a real algorithm engine rather than LLM generation, which signals determinism and trustworthiness. It says nothing about sequence length limits, input validation failures, or runtime 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?

Two compact lines with the purpose front-loaded and the return note trailing; nothing is padded. The bracketed category label and colon-delimited return clause make it scannable, though they edge slightly toward name-restating 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?

For a two-parameter, read-only prediction tool with no output schema, the description covers what it does and what it returns, which is the key missing piece. Only edge-case behavior (invalid or non-protein sequences, default modification set) is left unaddressed.

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 both parameters are already documented in the input schema, including the phosphorylation/glycosylation values. The description mentions the same modification types but adds no extra meaning such as defaults when 'modifications' is omitted or accepted input format for the sequence.

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 names a specific action and resource: predicting phosphorylation/glycosylation modification sites ('用户要预测磷酸化/糖基化等修饰位点'). This distinguishes it from protein-related siblings such as act_protein_digest, act_protein_physchem and act_protein_enrichment, though it never explicitly contrasts itself with them.

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 an implicit trigger condition by describing the user intent ('user wants to predict modification sites'), which is enough to route a request. However, there are no exclusions, no prerequisites (e.g. sequence format/length), and no named alternative tool for adjacent protein analyses.

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