add_marker

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

No annotations are provided, so the description carries the full burden. It discloses a behavioral detail ('then confirm it exists'), which adds some transparency about the tool's verification step. However, it does not explain side effects, failure handling, or whether it modifies the active sequence in a way beyond the obvious add. This is a moderate level of disclosure.

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 two sentences long, front-loaded with the main action, and every sentence adds value. The first states the core function, the second provides practical use cases. No wasted words.

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 simplicity (4 params, no output schema, no annotations), the description covers the essential aspects: what it does, when to use it, and a hint of behavioral verification. It does not explicitly describe the return value, but 'confirm it exists' implies a confirmation result. This is reasonably complete for the tool's complexity.

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 all four parameters documented in the schema. The description does not add additional semantic meaning beyond the schema, so the baseline of 3 is appropriate. It neither compensates nor detracts from the schema's clarity.

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 clearly states the action ('Add a marker to the active sequence at a given time') with a specific verb and resource. It also mentions the confirmation behavior, distinguishing it from sibling tools like list_markers and delete_marker. The use cases ('noting beats, cut points or review comments') reinforce its purpose.

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 a clear usage context: 'Handy for noting beats, cut points or review comments.' This implies when to use the tool but does not explicitly mention alternatives or when not to use it. It provides enough context for selection without exclusion guidance.

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