session_install

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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false. The description adds useful contextual behavior beyond that: no browser or licence is required, it 'always answers,' and it returns text. This is sufficient for a non-mutating informational tool.

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 short and front-loaded with the core purpose. It contains a slight redundancy between 'Return setup instructions' and 'Returns installation steps as text,' but the final clause does clarify the output format, so the overall structure is still efficient.

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 that the tool has no parameters, no output schema, and annotations that already cover its safety profile, the description provides everything needed: target resources, trigger context, dependency constraints, and return type. An agent can select and invoke this tool correctly without further information.

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 has zero properties and schema description coverage is 100%, so the baseline for a 0-parameter tool is 4. There are no parameters to document, and the description does not need to compensate for any schema 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 states a specific verb and resource: it 'Return[s] setup instructions for the T3rnel Browser extension and for the free standalone automation browser.' It is clearly distinct from all sibling tools, which are runtime/automation operations, and it identifies itself as the fallback tool when another tool reports the extension is missing.

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 gives an explicit trigger: 'call it when another tool reports the extension is missing.' It also explains why this is the right fallback: 'Needs no browser and no licence, so it is the one tool that always answers.' No sibling tool performs installation instructions, so no alternative routing is needed.

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