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

Annotations already declare readOnlyHint=false, destructiveHint=true and openWorldHint=false, so the safety profile is covered. The description adds one useful scope fact (no deletion). It says nothing about partial-update semantics, whether omitted fields are preserved, permission requirements, or the optimistic-concurrency parameter.

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 short sentences with zero filler, and the mutation scope is front-loaded before the exclusion. Nothing redundant or padded.

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?

An output schema exists, so return values need no explanation, but for a 24-parameter mutation tool with near-zero schema descriptions the definition is far too thin. Key facts an agent needs, such as partial-update behavior and the purpose of expectedUpdatedAt for concurrency, are absent.

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?

With 24 parameters and only ~8% schema description coverage, the description carries most of the burden but supplies almost no parameter meaning. It only implies that an existing session is targeted, which loosely maps to the required sessionId; the other 23 fields, the two enums and expectedUpdatedAt are left entirely to the schema.

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 (edits) and resource (existing TuneWorks driving session), which is clearly distinct from create_session, copy_session and archive_session. It does not explicitly name those siblings or state what an edit means relative to them, so it stops short of the top mark.

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?

'Deletes are not supported' is a genuine when-not hint, so the agent knows not to reach for this tool to remove a session. However, it never says when to prefer this over archive_session, copy_session or update_setup, and gives no prerequisites such as needing an existing sessionId.

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