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

Annotations already indicate destructiveHint=true and idempotentHint=true, but the description greatly expands on these. It states partial update semantics, the exact condition object format and valid operators, restricted condition types (no BADGE_EXISTS, no IDENTITY_AGE_LT), the requirement that all conditions must hold, and that the response is 'the updated rule.' This exceeds what annotations capture and gives the agent full behavioral expectations.

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?

The description is concise and front-loaded: it states the purpose and partial-update behavior first, then the condition format, then constraints and the return value. Every sentence serves a purpose, with no filler. It is slightly longer than minimal but the density of domain-specific information justifies the length.

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?

Given the tool's complexity (8 params, deeply nested conditions, no output schema), the description covers everything an agent needs: how to update, what conditions are valid, what are the constraints (no badge references, no identity age LT), the confirmation requirement, and the return value. It also accounts for escalation rule alternatives. No critical information is missing, making it a self-contained guide for correct invocation.

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 each parameter already has a description. The description adds value by explicating the 'conditions' array structure—the most complex parameter—documenting allowed condition values, categories, threshold ranges, and the meaning of seconds. For other parameters like name and type, the schema already suffices. Thus the description meaningfully supplements the schema, particularly where the schema only lists properties but lacks domain rules.

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 states the action clearly: 'Update a badge rule' with a specific resource. It distinguishes itself from siblings like create_badge_rule and get_badge_rule by the verb, and adds domain-specific detail about partial updates and condition structure, leaving no ambiguity about what the tool does.

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?

The description gives explicit guidance on when to use this tool: 'Pass only the fields to change; omitted fields keep their values' and instructs to 'Confirm with the user first.' It also directs alternatives for unsupported condition types: 'use an escalation rule for those.' However, it does not explicitly contrast with create_badge_rule or list_badge_rules, but it is clear this is for modifying an existing rule, which is implied by 'update' and 'pass only fields to change.'

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