list_signals

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

With no annotations, the description carries the burden of behavioral disclosure. It explains the default scope, the return structure (Dict with scope, count, and files/signals), and notes that ctx is unused. It implies a read-only listing operation, though it never explicitly states there are no side effects.

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 well-structured with a clear first-line summary, followed by Args and Returns sections. Each part contributes value, but the 'ctx: MCP context. Unused...' note is a minor tangential detail that prevents a perfect score.

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 single-parameter list tool with an output schema, the description covers the default behavior, valid parameter values, return format, and usage intent. There are no significant gaps in context for an agent to invoke and interpret results 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 coverage is 0%, but the description fully explains the only parameter, scope, by defining each enum value ('disk' vs 'memory') and its behavioral consequences. This adds significant semantic meaning beyond the raw schema enum.

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 opens with a specific verb and resource: 'List signal files on disk or signals loaded in the repository.' It explicitly distinguishes the disk and memory scopes, making it clear what this tool does and differentiating it from related tools like load_signal and clear_signals.

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 provides clear usage context: disk scope is for 'use before loading' and memory scope is for 'seeing which signal_ids are available for analysis.' It does not explicitly name alternative tools or when not to use this tool, so it falls just short of a 5.

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