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

Annotations declare destructiveHint=true and idempotentHint=true, so the safety profile is already structured; the description adds real value by explaining the blast radius — StepEditor snapshots content at click time, so live cadences are unaffected. That clarifies a non-obvious consequence of an overwrite operation. It doesn't cover the admin-only restriction on target_user_id beyond what the schema already says, nor failure behavior on a bad id.

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 sentences, front-loaded with the mutation scope and followed immediately by the side-effect caveat and the alternative tool. The emoji markers are decorative but do not pad the content; every clause carries information.

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 6-param, fully-documented-schema mutation with annotations and no output schema, the description covers purpose, impact scope, and sibling routing adequately. Minor gap: nothing about what a successful update returns or how partial updates behave when only one field is supplied, though the schema implies optionality.

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 six parameters including target_user_id's admin restriction and the is_html enum are already documented in the schema. The description's field list (nome, assunto, corpo, formato) mirrors the schema rather than adding syntax, limits, or format constraints. 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 (Atualiza) plus the exact resource and the mutable fields (nome, assunto, corpo, formato) of an existing template. The 'BIBLIOTECA DE TEMPLATES DE E-MAIL' framing and the contrast with update_sequence make it distinguishable from create_email_template, delete_email_template and list_email_templates without opening any 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?

Explicitly says the edit does not touch cadences already in production and names update_sequence as the correct tool for that case, plus points at list_email_templates for obtaining the id. It never states the when-not for editing vs. creating a new template, but the actionable routing guidance is there.

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