send_message

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

Annotations only supply destructiveHint=false and a title, so the description carries most of the behavioral burden and adds nothing: no note on whether the send is idempotent, whether it fails on an invalid or archived spaceId, what permissions or membership the workspace requires, or what is returned (e.g., message id). For a mutation tool with near-empty annotations, this is a real gap.

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?

It is a single front-loaded sentence with no filler, which is structurally sound. The brevity is under-specification rather than verbosity, so it is penalized elsewhere rather than here.

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 three-required-parameter mutation with no output schema, thin annotations, and only one-third schema coverage, the description is far too sparse. An agent cannot confirm the address format for workspace, the accepted message payload form, or the relationship to reply/update siblings from this definition.

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 only 33%, with spaceId the sole documented parameter, yet the description adds no meaning for the remaining parameters. Nothing explains what workspace expects (name vs. id) or whether message supports markup, mentions, or length limits — the one parameter whose semantics are most consequential for a send tool.

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 pairs a specific verb ("Send") with a clear resource ("a message") and scope ("channel or direct message"), which is enough for an agent to know what happens. It stops short of distinguishing itself from nearby siblings like reply_to_message or update_message, so the agent must infer the boundary from names alone.

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?

There is no when-to-use guidance at all: nothing says when to send a new top-level message versus reply_to_message, update_message, or start_direct_message. The only usage-adjacent signal is that spaceId comes from list_channels/create_channel/start_direct_message, which is documented in the schema rather than the description.

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