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

With no annotations, the description carries the entire burden and does so well: it discloses the pricing model (charged once per call, not per sequence), partial-failure behavior (failed slots carry {error: true, message, sequence} without aborting the batch), the hard cap rejecting rather than truncating, and guaranteed no silent short results. These are exactly the behavioral traits an agent needs and cannot get from structured fields.

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?

Front-loaded with the core promise, then failure/limit behavior, then a compact parameters block and return shape. Every sentence earns its place and the structure is easy to scan.

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 batch tool with an output schema (which carries return shape) and no annotations, the description supplies the missing behavioral context: cost model, batch size limit, error containment, and ordering. Nothing an agent needs to call this correctly is absent beyond the peripheral api_key.

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 0%, so the description must compensate. It documents the critical 'sequences' parameter (amino acid sequences, max 100) which adds real meaning, but the second parameter api_key is never mentioned. Covers the important parameter but leaves one undocumented.

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 (profile), resource (protein sequences), scope (up to 100 per call), and explicitly ties itself to the sibling covabio_protein_profile ('same 30+ biophysical properties ... per sequence'). An agent can distinguish this batch tool from the single-sequence sibling without opening the schema.

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?

Names concrete use cases ('candidate panels, variant series, or a whole FASTA out of covabio_parse_fasta') and the cap condition (over 100 rejected, so split the batch). It differentiates against covabio_protein_profile by implication ('per sequence') but never explicitly says to use the single tool for one sequence, so it stops short of full when/when-not framing.

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