set_state

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

With no annotations, the description carries the behavioral transparency burden. It discloses the persistence location 'data/state.json', which is useful context, but it does not reveal whether existing keys are overwritten, whether value is optional despite the schema, or any potential side effects. This is a minimal but not misleading disclosure, so it earns a 3.

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, clear sentence that immediately states the action and target. There is no wasted text, and the key information is front-loaded. This is appropriately concise for the tool's simplicity.

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 simple two-parameter setter with no output schema, the description is adequate but incomplete. It lacks details about overwrite behavior, the optional nature of 'value', and how the stored state might be retrieved or affected by other tools. The minimalism leaves some gaps, but the core purpose is clear enough to warrant a mid-range score.

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. However, it only repeats the concept of 'clave/valor' (key/value) without adding meaning about the types, formats, or optionality of the value parameter. It does not explain what kind of objects are acceptable or how the key is used, leaving parameter semantics largely undefined.

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 clearly states the tool's function: 'Guarda una clave/valor en el estado interno del MCP (data/state.json)' (saves a key/value in the internal MCP state). It uses a specific verb and resource, and the mention of 'internal state' distinguishes it from sibling tools that operate on custom patterns, presets, or ecosystem data.

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?

No guidance is provided on when to use this tool versus alternatives, nor are there exclusions or prerequisites. The description does not mention when a user should prefer set_state over other state-related tools like storage_status or the various add_* commands.

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