lib_get_project_library_uuid

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

Annotations already declare this a safe, idempotent, closed-world read, so the bar is low. The description still adds real value by disclosing the edge-case return behavior (undefined when no project is open), which the annotations cannot express.

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?

One front-loaded sentence with a parenthetical for the edge case; every clause earns its place and nothing is 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?

For a parameterless getter with no output schema, the definition covers the one thing an agent needs beyond the schema: what comes back when there is no open project. Missing only an explicit pointer to the sibling UUID getters.

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?

The single instance_id parameter is fully documented in the schema (100% coverage), including the multi-instance rule and the list_instances pointer. The description adds nothing about the parameter, so the 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 (get) and resource (UUID of the current project's library), which is more precise than the sibling getters. It does not, however, explicitly distinguish itself from lib_get_personal_library_uuid or lib_get_system_library_uuid, leaving the agent to infer the difference from the 'project' qualifier alone.

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 only implied: the tool is clearly the project-scoped variant, and the parenthetical hints at a precondition ('if no project is open'), but no alternatives are named and no explicit when-to-use guidance is given.

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