zipviz_send

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

With no annotations, the description carries the full behavioral burden and does so well: it discloses that signing is mandatory and local, names the default key path (~/.zipviz/keys/<as>.key), the metadata location of the signature (params.message.metadata.zipviz), and the verification endpoint. It still omits side-effect/error behavior (what happens if the recipient tunnel lookup fails, delivery confirmation, rate limits), so it is not exhaustive.

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?

Front-loaded with the action, then supporting detail in three dense sentences with no filler. The signing paragraph is long but every clause (key path, metadata block, verify endpoint, no unsigned path) carries operational weight.

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?

There is no output schema and the description says nothing about what the call returns (delivery receipt, message id, or error shape), which matters for a network send. Signing semantics are well covered, but the return/error contract and any recipient-resolution failure mode are left for the agent to discover.

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 the baseline is 3; the description earns an extra point by adding the default key location for `as` and restating the signing contract that governs how `as` is used. It does not add anything beyond the schema for `domain`, `message`, or `envelope_v`.

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 message to an agent on the ZipViz network") and goes further by describing the mechanism: tunnel-URL lookup followed by an A2A POST. The always-signed behavior implicitly separates it from zipviz_sign_message, but no sibling is named explicitly, so it stops short of 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?

Usage is implied rather than stated: the agent learns it must use this path because "there is no unsigned send path" and strict signed-inbound recipients reject unsigned messages. However, there is no explicit guidance on when to use this versus zipviz_sign_message, zipviz_verify, or zipviz_lookup, and no prerequisites or failure conditions are given.

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