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

Annotations already declare this is a non-read-only, non-destructive, non-idempotent write, so the safety bar is lower. The description earns credit by disclosing an authorization prerequisite ('Requires project_systems:write scope'), which is exactly the kind of context annotations cannot convey. It stops short of explaining duplicate-link behavior, which matters given idempotentHint=false.

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 very short sentences, action first and authorization second. Nothing is padded and nothing extraneous is included.

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 simple two-parameter association tool with no output schema and annotations covering the safety profile, the essentials are present: the action, the two entities involved, and the required scope. The only meaningful omission is what happens when the link already exists (idempotentHint=false suggests a failure mode worth warning about).

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 100% and both parameters are required UUIDs with their own descriptions, so the schema carries the full burden. The description adds no syntax, ordering, or constraint 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?

The description gives a specific verb and resource — 'Link a system to a project' — which precisely characterizes this as a junction/association creation, more informative than the tool name alone. However, it does nothing to distinguish it from the many near-identical siblings such as create_project_system_class, create_project_system_group, or create_project_asset.

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?

There is no explicit when-to-use guidance, no prerequisites, and no mention of alternatives or follow-up tools (e.g. list_project_systems or delete_project_system). The intended usage is only inferable from the one-line purpose statement, matching the 'no guidance' band.

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