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

Annotations already declare destructiveHint=true, idempotentHint=true and readOnlyHint=false, so the safety profile is covered by structured data. The description adds no behavioral context beyond restating the updatable fields — it does not warn that deal_value and status overwrite existing values, that the note is appended to the timeline rather than replacing, or what the call returns.

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, front-loaded with the concrete effect and followed by a usage hint; nothing is padded. The second sentence is slightly vague but does add intent rather than repeating the name.

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 an 8-parameter destructive mutation with no output schema, the description leaves gaps: it never clarifies that contact_id identifies the deal, never states the note-versus-overwrite semantics, and never mentions the return value. Sibling routing (update_contact vs update_deal) is the biggest omission.

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%, with enum values and funnel-resolution guidance already documented per parameter, so the baseline is 3. The description only echoes a subset of the fields and adds no format or edge-case meaning beyond the schema.

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 gives a specific verb+resource ("Atualiza dados de uma negociação") and enumerates the mutable fields (deal value, pipeline stage, status, note), so the agent knows exactly what the tool touches. It does not, however, distinguish itself from close siblings like update_contact or update_contact_status, which take the same contact_id and status, leaving real ambiguity about which tool to pick.

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?

"Use para mover oportunidades pelo funil de vendas" implies a sales-funnel context but gives no explicit when-to-use/when-not-to-use rules and names no alternative. The critical prerequisite for stage changes (resolving the funnel via list_pipelines) is only in the schema, not the description.

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