add_tag

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

Annotations already declare readOnlyHint=false, idempotentHint=true, and destructiveHint=false, so 'Safe to repeat' largely restates structured data. However the description adds genuinely new behavior: the read-modify-write of the tag list that preserves existing tags, and the auto-creation of missing tags.

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?

Four tight sentences, each carrying distinct information, with the core action front-loaded and the sibling pointer last. 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?

Explicitly states the return value ('Returns the updated lead'), covers idempotency and the tag-creation side effect, and points to list_tags. For a two-parameter mutation with no output schema, only minor details like failure modes are absent.

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 coverage is 100%, including the lead_id source and case-sensitivity of tag_name, so the baseline is 3. The description only adds that tag_name may not exist yet and will be created, which is marginal 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?

States a specific verb and resource ('Attach a tag to a lead by name') and immediately clarifies a secondary effect (creating the tag when absent). This is easily distinguished from the sibling remove_tag and from generic lead writers.

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?

Gives a clear condition ('Safe to repeat') and routes the agent to list_tags for discovering existing tag names. It does not explicitly contrast with remove_tag or explain the alternative of not tagging, but the context is clear.

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