Probe capture permissions

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

Annotations only declare readOnlyHint=true and openWorldHint=false, so the description adds real value: it states the operation is non-recording, requires no user click, and is refused during an active recording. That refusal constraint is meaningful behavioral context an agent would otherwise miss.

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?

A single dense sentence front-loaded with 'Diagnostic:' and with no wasted clauses — each sub-clause (no user click, permission scope, recording refusal) earns its place.

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 read-only, single-optional-param diagnostic with no output schema, the description conveys what the check evaluates (capture feasibility and permission grants). It stops short of describing the return shape, but the tool is simple enough that this is a minor gap.

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?

Only one parameter, tabId, and schema description coverage is 100% with the default behavior (active tab of last focused window) fully documented in the schema. The description adds nothing beyond the schema, so the baseline 3 is appropriate.

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?

Names a specific verb (check) and a precise resource (whether the extension can capture the target tab without a user click, plus which optional Chrome permissions are granted). This clearly distinguishes it from siblings like get_status, screenshot, or start_recording.

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 'Refuses while a recording is running' clause is an explicit when-not condition, telling the agent this is a pre-recording diagnostic. It doesn't name an alternative tool for the same check, but the context is well established.

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