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

Goes well beyond annotations by disclosing the required OAuth scope (training:write), the created resource's visibility (private workout), the return payload (a link to share with the user), and retry semantics for idempotency_key. Annotations only cover the generic write/idempotent/safe profile; the description supplies the operational detail an agent needs.

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 short sentences, each carrying distinct content: prerequisite gate, action and output, permission requirement, retry semantics. The gating condition is front-loaded, and nothing is redundant with structured fields.

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 write tool with a confirmation gate, an output schema present, and full schema coverage, the description covers the preconditions, permissions, side effects, and downstream instruction (share the link). Nothing an agent needs to invoke it correctly is missing.

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 three parameters are already documented, including the idempotency_key reuse rule and the confirmation gate. The description restates the idempotency behavior but adds no syntax or format detail beyond the schema, so 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+resource ('saves that workout to the connected Phorme account') and scopes it precisely as the second half of a two-step flow. It clearly distinguishes itself from preview_workout_import, which it names as the prerequisite.

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 gives the when-to-use condition ('only after preview_workout_import returned a preview and the user clearly said to save it') and names the alternative tool the agent should have already called. It also implies the when-not condition: do not call before a preview and explicit user confirmation.

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