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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, so safety is covered structurally. The description nonetheless adds operational limits not present in the annotations – 64 KB input, 1 s per call, 1 MB result – plus an explicit determinism guarantee, which is real added value. It stops short of describing output shape, but an output schema exists to carry that.

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 operation and the 'when/not for' routing, with limits last. The Spanish and English copies are redundant for an agent reading both, but the structure is otherwise tight and each field block earns its place.

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?

This is a deterministic 3-parameter math tool with a full output schema, so return values need no prose. Purpose, routing, side effects, determinism and hard limits are all present; nothing an agent needs to invoke it correctly is missing.

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 all three parameters are documented in the schema, including the a ≠ 0 constraint. The description only restates the polynomial form ax² + bx + c = 0, adding mapping context but no new semantics such as numeric range or precision behavior. Baseline 3 applies when the schema does the heavy lifting.

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+resource: solves ax² + bx + c = 0 and returns real or complex roots, the discriminant and the vertex. An agent can separate it from the closest sibling, linear-system-solve, purely from the description, since the negative case names that sibling explicitly.

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?

Provides an explicit 'Cuándo/When' condition (a numeric result must be exact or reproducible rather than estimated) and an explicit 'No para/Not for' exclusion that names the alternative, linear-system-solve, with its problem shape (Ax = b). Both the inclusion and exclusion criteria are given rather than inferred.

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