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

Annotations already declare readOnly=false, destructive=false, openWorld=true, idempotent=false. The description adds value beyond them: it clarifies that publish=true makes the version the live manifest immediately while omitting it leaves an unpublished draft, and that the service validates the definition on submit. It stops short of saying whether an unpublish/rollback path exists once a version goes live.

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?

Three sentences, front-loaded with the core operation, then the schema-source instruction, then the publish switch, then the sibling exclusion. No filler; every clause carries routing or behavioral information.

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 mutation against a nested free-form object, the description supplies the missing pieces: where the JSON Schema lives, that it is validated on submit, what publish does, and which sibling handles brand-new apps. Return values are covered by the existing output schema, so nothing material is left unexplained.

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 coverage is 100%, so the baseline is 3, but the description adds real meaning: it ties publish to its live-manifest consequence and tells the caller where to obtain the definition contract (get_app_definition_schema, or copy via get_*_version). That is more than a restatement of the schema text.

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 ('add a new version to an EXISTING app (by app_id)') and scopes it to changing the membership selector or display. It also explicitly disambiguates from the sibling create_app, so an agent can route without opening either 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 condition for use (modifying an existing app's selector/display), names the alternative for the opposite case ('For a brand-new app, use create_app'), and routes to get_app_definition_schema for authoring. The publish=true vs. draft default fork is spelled out as a decision the caller makes.

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