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

Annotations cover safety (readOnlyHint=false, idempotentHint=true) but the description adds substantial behavior beyond them: 60-second expiry, single live-connection limit, 64 unexpired ticket cap, compaction semantics (not a lifetime reconnect quota), transport-only credential handling, and non-disclosure of upstream URL/credentials.

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?

Four dense sentences, front-loaded with the primary return value and its lifetime. Every sentence carries operational information (expiry, limits, compaction, credential transport, non-disclosure), though the compaction clause is slightly expositional.

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?

With an output schema present, return values need not be fully described, and the description still covers the key behavioral constraints. The remaining gap is parameter meaning for the two required inputs, which is left to the schema-less names.

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 0% for two required parameters (session_id, idempotency_key), yet the description explains neither. It only clarifies that the lease bearer is not a tool argument, which distinguishes it from the params but does not compensate for the undocumented session_id and idempotency_key.

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: mint/return a single-use Ausca CDP relay URL for a ready lease. This clearly differentiates it from siblings like ausca_browser_session_close and ausca_browser_session_status, which manage or inspect sessions rather than mint connection tickets.

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?

The 'for a ready lease' precondition and the instruction to place the lease bearer on the HTTP/MCP transport (never in arguments) give clear usage context. However, it does not explicitly name alternative siblings or state when-not-to-use, so it falls short of a full 5.

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