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

Annotations already declare the tool as readOnly, idempotent, and non-destructive, so the safety profile is covered. The description adds the output components (root, quality, intervals) but does not disclose any additional behavioral traits such as error handling, edge cases, or format constraints. It adds some value but not rich context beyond the annotations.

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 a single, well-structured sentence that immediately states the action and outputs. It avoids redundancy and includes the key caveat about the key in a natural way. Every word earns its place.

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?

There is no output schema, so the description needs to explain return values; it does so by listing root, quality, intervals, and roman numeral + function. It also clarifies the role of the optional key. For a straightforward read-only analysis tool, this is sufficient, though it does not mention error behavior or chord notation specifics, keeping it just short of full completeness.

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 0%, so the description must compensate. It does explain that 'key' is used to derive roman numeral and function (implying it is optional, as the schema does not require it), but it does not describe the expected format for the chord or key strings. This adds some meaning beyond the schema but leaves significant gaps.

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 uses a specific verb 'Parse' and a clear resource 'chord', and enumerates the outputs: root, quality, intervals, and roman numeral + function. This clearly distinguishes it from sibling tools like generate_voicing or reharmonize, which imply creation or alteration rather than analysis.

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 implies usage for chord analysis and mentions that a key is needed for roman numeral/function, but it does not explicitly state when to use this tool versus alternatives or provide any exclusion criteria. It provides no direct comparison with siblings, so usage guidance is only implied.

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