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

Annotations already declare the mutation profile (readOnlyHint=false, destructiveHint=false, idempotentHint=false), so the description adds value by disclosing the authorization requirement ('Needs the permission to change tasks') and the visibility/signature behavior ('It is signed with your name', 'every assistant reads both'). It does not say what happens if a duplicate is submitted, so it stops 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?

It is dense and front-loaded: the purpose leads, the exclusion and alternative follow, and operational details (permission, signature, scope, duplicate check) come last. Slightly long with several chained clauses, but nearly every clause carries routing or behavioral information.

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 4-parameter write tool with no output schema, the description covers purpose, exclusion criteria, alternative tool, required permission, attribution, project scope, and duplicate-handling workflow. Nothing an agent needs to call this correctly is missing.

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 coverage is 100% and the schema already documents each parameter, so the baseline is 3. The description adds meaning by tying project scoping to behavior ('Leave project blank when it applies to everything' combined with 'every assistant reads both'), clarifying the blast radius of an omitted project rather than just restating the field.

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 concrete verb+resource ('Leave a context note for the next AI assistant') and immediately defines what qualifies as a note ('a FACT you worked out that is nobody's choice -- how the code works, a trap, where something lives'). It explicitly contrasts itself with fenbs_add_decision, so an agent can distinguish it from the nearest sibling without opening either schema.

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?

It states the when ('a FACT you worked out'), the when-not ('NOT for rules, preferences or anything a person decided'), the alternative for the excluded case (fenbs_add_decision, with a sub-case rule), and a pre-flight check ('Check fenbs_list_context_notes first ... change it with fenbs_update_context_note rather than adding one that contradicts it'). This is about as complete as usage routing gets.

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