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

Adds substantial behavior beyond the annotations: this is a chain write that only produces an unsigned intent, and nothing is committed until the agent signs locally and calls geode_submit_intent. Annotations (readOnlyHint=false, destructiveHint=false, openWorldHint=true) cover the safety profile, but the description does not cover fees, failure modes, or the result of calling it when the recipient has not allowed the sender.

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, zero filler. The purpose leads, then the write/intent mechanics and required follow-up calls are packed into the second sentence, which is exactly the ordering an agent needs.

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 four-parameter write tool with no output schema, the description covers the essential mechanics (intent, signing, submission) and the recipient-permission precondition. What is missing is the failure/error expectation when the precondition fails and any routing hint toward the paid/group/list message variants.

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 each of the four parameters is already documented in the schema. The description only echoes `signer`'s role in the signing workflow and adds no format or constraint detail (e.g., byte limits, SS58 form) beyond the schema, so the baseline 3 applies.

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 resource (send a private message to an account) and adds a scoping qualifier ('that has allowed you to message it') that separates it from geode_messaging_send_paid_message, send_message_to_group, and send_message_to_list. An agent can identify the right sibling without opening any schema.

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?

Gives the precondition for use (recipient must have allowed you to message it) and a clear end-to-end flow: prepare intent, sign with geode-local-signer, submit with geode_submit_intent. It stops short of naming the alternative messaging tools and when to prefer them (paid message, group, list), so it is strong context without explicit exclusions.

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