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

Annotations already declare readOnly, idempotent, non-destructive and closed-world, so the safety profile is fully covered. The description adds value beyond that by disclosing sort order ('newest first') and the status taxonomy (proposed, announced, in effect, resolved), which tells the agent how to interpret each record. It stops short of 5 because it says nothing about behavior when the filter matches nothing or whether historical records are pruned.

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 compact sentences, front-loaded with what the tool returns and how it is ordered, then the filter. Every clause carries information: source, ordering, status values, filter dimension. Nothing is redundant with the name or 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 simple, annotation-covered, two-parameter read tool with no output schema, the description does the work that matters: it describes the record shape (dated, ordered, status-marked) so the agent understands return values without an output schema, and the schema fully covers both inputs. Nothing essential 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%: limit has a default, min/max and description, and subclass has a regex pattern plus an example. The description only restates the subclass filter in prose and adds no format hints or semantics beyond the schema, so the baseline of 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 resource (Tern's dated record of Australian visa policy changes) and the shape of the data (newest first, status-labelled). The resource is naturally distinct from the siblings (fees, processing times, WHM cap), but the description never explicitly contrasts with them, so it lands just short of the top mark.

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 by the resource name: you call it to read policy changes. There is no explicit 'use this when' statement, no exclusion ('not for fee changes – use get_visa_fees'), and no note on what to do for subclass-specific questions versus the broader profile tools.

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