session_activate

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

No annotations were provided, so the description fully bears the burden of behavioral disclosure. It details the matching priority (exact ID wins), the fallback substring matching, and the error condition when multiple candidates are found, providing clear behavioral insight.

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 two sentences long, front-loading the core purpose, then efficiently explaining parameter behavior. Every sentence adds value with no waste.

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?

Given the simplicity of the tool (one parameter, straightforward action) and the existence of an output schema, the description covers all necessary context: what the tool does, how the parameter works, and error handling.

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 input schema provides a description of the `session_id` parameter, but the tool description adds crucial behavioral semantics: how exact and substring matching works, and that ambiguous matches return an error listing candidates. This goes beyond the schema's description.

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 action: 'Set the active Godot editor session for subsequent tool calls.' It uses specific verb ('Set') and resource ('active Godot editor session'), and distinguishes from sibling tools like 'session_manage' which likely manages sessions rather than activating one.

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 explains when to use the tool (to set active session) and how the parameter matching works (exact ID vs substring, with error behavior if ambiguous). It does not explicitly mention when not to use it or point to alternatives, but the context is clear enough.

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