list_processors

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

With no annotations provided, the description carries the full burden. It clearly discloses that the tool returns failed-to-load plugins so typos are visible, and explains the architectural constraint preventing runtime loading (arbitrary code execution). The security rationale adds genuinely useful behavioral context beyond bare functionality.

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?

Well-structured with the purpose line first, a clear explanation paragraph, and a marked 'Returns' section. Efficient use of space; each sentence contributes meaning. Slightly longer than strictly minimal, but all content is substantive rather than filler.

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 zero-parameter enumeration tool with an output schema present, the description covers purpose, source/provenance, loading behavior, and failure visibility. The return-value details are useful supplement to the output schema. Coverage of why runtime loading is disallowed adds valuable completeness around constraints.

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?

The tool has 0 parameters, so the schema fully describes the input surface. The description compensates by explaining what the return payload will contain (available processors with parameters plus failures), which is itself a form of parameter/output semantics. Baseline for 0 params is 4, and the description earns it by describing the result composition.

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?

Uses a specific verb+resource combination ('List real-time processors available to attach') and clearly states the scope ('and where they came from'). It distinguishes its purpose from siblings like attach_processor, processor_status, and run_processor by focusing on enumeration of availability and provenance.

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 explains when processors appear versus when they don't, naming the three server-side loading mechanisms (entry point, EEG_MCP_PLUGINS, EEG_MCP_PLUGIN_DIR). It also clearly states an exclusion ('cannot be loaded from a tool call') and justifies it with a security rationale, giving the agent concrete guidance on expectations.

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