Thunderbird error console

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

Annotations already declare readOnly/idempotent/non-destructive/closed-world, so the safety profile is covered. The description adds genuinely non-obvious behavior: credentials are redacted inside Thunderbird before transmission, and bridge `console.*` lines are merged with native error-console entries by timestamp. That is real context beyond the annotations.

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 purpose statement is front-loaded in the first line, followed by filtering guidance and then the behavioral caveats. Every sentence carries distinct information — ordering, filter semantics, redaction, and merge behavior — with no 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?

With an output schema present, return values need no explanation, and annotations cover the safety profile. The description fills the remaining gaps (filtering, redaction, source merging, ordering) well, but omits any handling of the `limit` parameter, which an agent needs to control result size.

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 carry both parameters. It explains `contains` richly (what kinds of values to pass and what each selects) but never mentions `limit` or its default of 100, leaving one of two parameters undocumented anywhere.

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 names a specific resource (Thunderbird's error console) and a specific scope ('recent lines', 'newest last'), so an agent immediately knows what it returns. It does not explicitly contrast itself with the near siblings tb_diagnostics or tb_events, which is the only thing keeping it from a 5.

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?

It tells the agent how to narrow results with `contains` and gives concrete example values ('tbmcp', an add-on id, a source filename), which is useful operational guidance. It never says when to reach for this tool versus tb_diagnostics or tb_events, and gives no exclusions, so tool-selection guidance is only implied.

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