gmail_summarize

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

With no annotations, the description carries the full burden; it usefully discloses the gemini_unavailable error condition, which is real behavioral context an agent can't get elsewhere. It omits other material traits: that this drives the Gmail UI (opening/targeting a conversation), that it can take up to the 120s timeout, and whether the summary replaces or adds to the view.

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?

Two sentences, front-loaded with the action and followed immediately by the one precondition that matters. Nothing is redundant or buried.

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 5-parameter, zero-annotation, output-schema-less tool, the definition leaves gaps: it never says what comes back (summarized text, a screenshot, a UI state change) or that the operation manipulates the live Gmail view. The error disclosure helps, but not enough to be fully self-sufficient.

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 100%, so every parameter (index, query, folder, timeout, expect_subject) is already documented with its interaction rules. The description adds no parameter-level meaning beyond the schema, which is the correct baseline of 3.

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?

States a specific verb and object ('Summarize a conversation with Gemini in Gmail') plus the underlying UI affordance ('Summarize this email'), so the agent knows exactly which action is triggered. It does not, however, distinguish itself from the sibling gmail_gemini, which plausibly covers the same Gemini-in-Gmail surface.

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 only conditional given is a failure mode ('Raises gemini_unavailable when the account has no Gemini in Gmail'), not a when-to-use rule. Nothing says when to summarize versus simply reading the thread with gmail_read, or how this differs from gmail_gemini.

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