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

readOnlyHint=true already covers the read-only safety profile, so the description need not restate it. It adds genuine behavioral context beyond the annotation: the 8-result cap and the free (no-credit) behavior. openWorldHint=false is not contradicted; nothing in the description conflicts with the annotations.

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 short sentences with zero waste, purpose front-loaded ('Autocomplete') before the constraint and cost note. Every word 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?

For a low-complexity single-parameter autocomplete tool with readOnly annotation, the description covers what it returns (up to 8 Argentine companies matching partial text). Minor gaps: the return format is not described (no output schema) and the sibling routing to buscar_empresas is left implicit, but these are small against the tool's simplicity.

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% — the q parameter is already documented ('texto parcial, mínimo 2 caracteres'). The description reinforces the 'partial text' semantics but adds no syntax or format detail beyond the schema, so the baseline 3 applies.

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 ('Autocomplete' / 'matchean') and a specific resource ('empresas argentinas') with a concrete limit (hasta 8). The autocomplete framing implicitly distinguishes it from the sibling buscar_empresas (full search), though it does not name the 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 a useful selection cue — 'Gratis (no consume créditos)' — telling an agent this is the zero-cost option among credit-consuming search tools, suitable for pre-filtering candidates. However, it does not explicitly state when NOT to use it or name the alternative (buscar_empresas) for full searches.

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