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

Annotations already declare readOnlyHint=true, idempotentHint=true and destructiveHint=false, so safety is covered; the description nonetheless restates 'Read-only' (redundant) and adds genuinely useful context: the null case, and that queued count excludes postponed questions. It stops short of explaining side effects on the queue or what 'evidencia' contains.

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 behavior and the null case in the first sentence, with the decision linkage and return shape following. The 'Read-only' line duplicates the readOnlyHint annotation and is the one sentence that doesn't fully earn 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?

With no output schema, the description responsibly documents the return shape ({pregunta: {...} | null, pendientes}) and the meaning of pendientes. It leaves the internal fields (entity_a, entity_b, reason, evidencia) uninterpreted, which is a minor gap for an agent that must act on them.

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?

Zero parameters, so the baseline of 4 applies; there is nothing for the description to disambiguate. The description correctly focuses its effort on the return payload instead of inventing parameter guidance.

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 ('Return') and resource ('the next pending entity-merge doubt'), including the null-case behavior, and anchors it to a sibling ('same shape as one item of get_merge_doubts'). An agent can distinguish it from the list-shaped sibling and from decide_merge_proposal without opening a 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?

It names the follow-up action explicitly ('The decision is applied with decide_merge_proposal') and clarifies that 'pendientes' excludes postponed questions. It lacks an explicit 'use this instead of get_merge_doubts when...' exclusion, but the get/pending framing implies the queue-draining usage.

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