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

Annotations only declare readOnlyHint=false and destructiveHint=false; the description adds the real behavioral payload (attribution of all subsequent calls, visibility in leases/receipts/audits, and the auto-provisioning default it overrides). It does not cover reversibility (how to unbind), ownership validation failure behavior, or whether the binding persists across sessions, so it falls short of a 5.

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 action and effect, then the when-to-use caveat, plus a docs URL. The rationale sentence is slightly long but earns its place by explaining why attribution matters; nothing is redundant with the title.

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 single-parameter identity tool with no output schema, the description covers what it does, when to use it, and the default it overrides. Missing only edge-case behavior such as invalid/unowned worker_id responses and how to undo the binding, which an agent might want before mutating connection state.

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?

One parameter with 100% schema description coverage, so the schema already defines worker_id including the UUID format and the "from whoami" discovery hint. The description restates the ownership constraint ("a worker you own") but adds no syntax, format, or discovery detail beyond the schema. 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 (point/bind) and resource (this MCP connection -> a worker you own) plus the downstream effect: every tool call from this connection is attributed to that worker. This is clearly separable from siblings like create_worker, whoami, or issue_worker_key, which concern worker creation or credentials rather than connection identity.

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 an explicit when-not and the default alternative: "Tango auto-provisions one worker per connection on first use; call this only to reuse an existing worker instead." An agent can decide between doing nothing and calling this tool without inference.

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