gmail_block_sender

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

With no annotations, the description carries the full burden and does disclose key traits: the action is immediate with no dialog, it is reversible via unblock, it affects future inbound mail, and it is gated behind confirm=true. It stops short of saying what happens to the existing conversation or thread contents after blocking.

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 effect is front-loaded in the first clause, and the remaining sentences cover reversal, scope exclusion, and the confirm gate without filler. The parenthetical UI-menu path is slight overhead, though it usefully anchors the behavior to the visible Gmail action.

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 an 8-parameter, no-output-schema mutation tool, the description covers effect, reversibility, precondition, and scope limits, with the schema filling in target selection. Only the post-block state of the current conversation and failure modes are left implicit.

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 including index, query, folder, message_index, and expect_subject is already documented in the schema. The description only echoes the confirm=true requirement and adds no interpretation of target selection or index resolution beyond what the schema states.

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 ('Block the sender of a message') plus the concrete effect ('their future mail goes to Spam'), so the outcome is unambiguous. It also draws a boundary against its reversal sibling by naming gmail.unblock_sender, and rules out self-addressed messages.

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 gives an explicit precondition (confirm=true) and an explicit exclusion ('Not offered for your own messages'), plus names the undo path. It does not, however, distinguish itself from adjacent siblings like gmail.mute, gmail.spam, or gmail.report_phishing, which an agent could reasonably confuse with blocking.

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