Update Contact Property

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

Annotations already declare destructiveHint=true, readOnlyHint=false and idempotentHint=false, so the agent knows this mutates state. The description adds real value by explaining that passing null clears description and fallback value, but it omits whether display_name can be cleared, whether the change is immediately live, and any permission requirements.

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 action and followed by the one non-obvious mechanic. No filler.

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 mutation tool with no output schema and annotations covering the safety profile, the description plus schema give enough to invoke it correctly. Minor gaps remain around live-effect and non-nullable display_name, but nothing blocking.

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 only 25% (just id), so the description carries the burden: it enumerates the three mutable fields and, beyond the schema's bare null types, explains that null on description/fallback_value means 'clear'. It does not mention the maxLength constraints or that display_name cannot be null.

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 (Change) plus resource (a custom field) and the exact editable attributes (display name, description, fallback value). It is clearly about contact properties rather than contacts, but does not explicitly distinguish itself from siblings like create-contact-property or update-contact.

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?

No statement of when to use this tool versus the create/get/list contact-property siblings, and no prerequisites. The only guidance is the null-clearing note, which is a mechanic rather than a usage condition.

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