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

Annotations only declare the mutation/destructive profile; the description adds real behavioral content beyond that — the conflict failure mode when an identical reading already exists, the routing advice to delete instead, and the possibility of a 'needs_confirmation' response. It stops short of stating reversibility or permission requirements for a destructive edit.

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?

Front-loads purpose, then usage, then failure behavior in roughly four tight sentences with no filler. The ALL-CAPS emphasis and quoted example are slightly chatty but earn their space by disambiguating the correction use case.

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 no output schema, the description carries the burden of describing returns and does mention the 'needs_confirmation' response and conflict failure, which are the two non-obvious outcomes. It is complete enough to call correctly, though it omits the ordinary success return shape and any permission prerequisites for this destructive edit.

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%, so all five parameters including the kind enum and the 500-char note limit are already documented in the schema. The description's gloss of `kind` as 'how the two relate' adds only marginal meaning beyond the schema's 'New edge type, in canonical direction.'

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 ('Edits an existing edge between two pages') and enumerates the two mutable fields, kind and note. This cleanly separates it from compass_links_create and compass_links_delete without the agent needing to open 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?

Gives an explicit triggering scenario ('Use to CORRECT a connection typed wrongly') with a concrete example, names the prerequisite source for link ids (compass_page_links_list), and routes the agent to an alternative ('delete this one instead') when the new reading already exists.

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