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

Annotations already declare readOnlyHint and idempotentHint, so the description's 'Read-only operation' is redundant, but it adds genuinely new context: the polling pattern, the concrete status values, the 0-100 progress range, and the required narrador:files scope or nrd_files_* API key. This is well beyond annotation coverage, though the auth detail could note failure behavior.

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 front-loaded sentences where each earns its place: purpose, usage sequence, return fields, and auth requirement. No filler or repetition.

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?

With no output schema, the description compensates by enumerating the return fields (jobId, status, progressPercentage, audioId), and it covers the polling lifecycle and auth prerequisites. An agent has everything needed to call and interpret this tool correctly.

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% and the single jobId param is fully documented in the schema (including the 'snapshot id' alias), so the description adds no parameter-level syntax beyond what the schema provides. Baseline 3 is appropriate.

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 ('Returns narrador files job status and progress') and distinguishes itself from siblings by naming create_files_job and get_files_result in its workflow. An agent can immediately tell this is the polling status endpoint.

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 says to poll after create_files_job until status is 'completed', and directs the agent to get_files_result once audioId is present. Both the when-to-use and the alternative/next step are named, so nothing is left to inference.

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